Mount Sinabung in Indonesia is just one of many volcanoes situated in populated areas

“In countries like Indonesia, or Japan, if you want to take a higher-income country, there isn’t much land that isn’t volcanic. Worldwide, we have this constantly increasingly population that needs space and food, and that drives people into areas that are closer and closer to the volcanoes.”

Alison Graettinger, volcanologist and postdoctoral researcher

University at Buffalo

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University at Buffalo geologist Michael Sheridan has studied
volcanoes including Mount Vesuvius in Italy and Popocatépetl
(“Popo”) in Mexico, both of which are situated in
populated regions.

BUFFALO, N.Y. — Mount Sinabung, whose
eruption over the weekend killed more than a dozen people and
destroyed homes and farms, is just one of many volcanoes around the
world that are located in populated areas.

Other examples include Mount Vesuvius in Italy,
Popocatépetl in Mexico, the Cascade Volcanoes in the United
States, and more.

University at Buffalo volcanologists Michael Sheridan and Alison
Graettinger can discuss risks surrounding some of the world’s
most dangerous mountains, and how communities in these areas can
protect themselves.

Michael Sheridan, PhD
Volcanologist and Professor Emeritus of Geology, University at
Buffalo

Contact info: Sheridan can be reached through Charlotte Hsu
in UB’s Office of Communications atchsu22@buffalo.eduand 716-645-4655.

Sheridan has studied high-risk volcanoes including Mount
Vesuvius in Italy and Popocatépetl (“Popo”) in
Mexico — both of which sit in the midst of large populations.
While he has not researched Mount Sinabung in particular, he can
discuss Vesuvius and Popo, as well as general hazards that
communities surrounding active volcanoes face.

His responses to some relevant questions:

Are there many volcanoes worldwide located in populated
areas?

There are a lot of them. The International Association of
Volcanology and Chemistry of the Earth’s Interior (IAVCEI)
considers this topic to be so important that they have meetings
every few years called “Cities on Volcanoes,” and these
meetings take place in actual cities that have the potential for
massive damage or disruption in the case of an eruption. Examples
of such cities include Quito, Ecuador. Mount Rainier in the United
States is also near the densely populated Tacoma/Seattle areas.

What can you tell us about Popocatepetl and Vesuvius, two of
the mountains you’ve studied? Both sit in populated
areas…

The activity of these volcanoes really hasn’t changed much
over the years, but the population around them has grown
dramatically. People are moving onto the slopes of these two
volcanoes, and settling in the flat plains that surround them.

Also, both Popo and Vesuvius have produced giant eruptions in
the past. Such extreme activity, separated by pauses of thousands
of years, is often dismissed by the local inhabitants and not
important to them.

However, both of these volcanoes have experienced a period of
rest that is longer than the average time span between really large
eruptions. So it’s getting more and more likely every year
that a gigantic eruption could happen near a large city, and nobody
wants to consider that.

Why are people reluctant to discuss the possibility of
extreme eruptions?

When extremely large events are infrequent, people don’t
think that there is a likelihood that it could happen in their
lifetime. They would say, “It will never happen while
I’m still alive, so I’m not going to be worried about
it.”

But such a disaster could actually happen at any time.
That’s what I reported about Vesuvius, and that information
caused a huge discussion in the Naples community.

Generally, what governments or managers want to hear is that
small events are much more likely; they would rather not talk about
the others, because it could create a panic in local communities.
Scientists must follow a narrow path here: Often, they must present
the evidence that they determine to be valid, but avoid saying
things that would undermine the local authorities’ ability to
manage the crisis.

Why is it so difficult to forecast volcanic activity?

Volcanic eruptions are one of the most complex natural phenomena
that you can imagine. Weather is much easier to forecast than
volcanoes, in terms of intensity, location, timing and
duration.

Volcanologists can consider previous eruptive activity, but the
actual volcano can always be a surprise: A new type of activity or
phenomenon could happen like never before. One example is the 1980
“blast” at Mount St. Helens, where many people died
even though the U.S. Geological Survey had a very cautious hazard
reduction plan.

What advances have been made in promoting safety in recent
years?

One of the major advances in assessing volcanic hazards is using
advanced computation and probabilistic approaches to understand the
hazards.

There’s a team of people at UB using new statistical
models to look at the probability of different volcanic hazards
affecting different areas around a volcano, and the relative safety
of specific sites surrounding a volcano. This kind of modeling can
provide useful information for hazard planning and management, but
it’s not an exact science.

Contact info: Graettinger will not available on Wednesday,
Feb. 5 or Thursday, Feb. 6. Graettinger can be reached through
Charlotte Hsu in UB’s Office of Communications at chsu22@buffalo.edu and
716-645-4655.

Yes. Indonesia, in particular, is a case where a lot of people
live very close. In the U.S., the Cascade Volcanoes are near
Seattle and other populated areas.

Why do people live around volcanoes?

Those areas have very fertile farmland. The volcanic ash turns
very quickly to fertile soil. In countries like Indonesia, or
Japan, if you want to take a higher-income country, there
isn’t much land that isn’t volcanic. Worldwide, we have
this constantly increasingly population that needs space and food,
and that drives people into areas that are closer and closer to the
volcanoes.

If your family lived there for generations, that’s your
home and it’s something you don’t want to leave.
It’s not a problem unique to volcanoes — people live in
Tornado Alley and in earthquake zones.

What hazards do communities near volcanoes face?

There’s quite a range. For people who live quite close,
they may regularly be dealing with ash on their properties, on
crops. You can’t hang your laundry outside, so it can be
quite the inconvenience even at a small scale.

As the eruption grows, the ash can poison livestock. You can
have things like roof collapse due to ash build-up.

Some communities will be in the path of mud flows, which are
called lahars — that’s an Indonesian word — and
pyroclastic flows, which can reach up to 450 miles an hour.
It’s not something you can run or even drive away from.
That’s why it’s important to evacuate when you’re
told to.

How can people stay safe?

If local authorities start closing areas, it’s very
important to abide by those instructions. Sometimes people
don’t want to leave — these are their homes — but
it’s important to evacuate. Pyroclastic flows are very rapid,
so it’s best to be away from the area before they begin.

We have short memories as humans. We forget big storms; we
forget when a long time has elapsed since the last big thing. If we
don’t see it in our lifetimes or our parents’
lifetimes, it’s difficult to understand the scale of what
could happen.

During an eruption that’s already occurring, staying out
of valleys and finding high ground is the important thing.

How easy is it to predict when a volcano is going to
erupt?

I try and avoid the word predict, because that implies more
accuracy than we can have. It’ll never be exact. What we do
is we try to forecast reasonably: If you know what normal behavior
is and you see changes, that can be a sign that something is about
to happen.

In some case we don’t get much warning at all, and in some
cases you may see signs a few days before. It can be tricky for
local authorities, because if you tell people to evacuate too soon,
they can get very frustrated if they have to stay away for a long
time.